Study on mineral structural stability of marine 1nm manganate

In order to study the phase transformation between 1nm manganate and 0.7nm manganate, a series of Slum Me~(2 ) manganates were made after the synthetic 1nm Na~ manganate substituted with different kinds of divalent cations. The X-ray diffraction analysis of wet S1nm Me~(2 ) manganates after 24 h room temperature dry showed that their basal d-spacing had been changed, indicating that there was phase transformation between 1nm and 0.7nm manganates. Take 1nm manganates with unstable structure collapsed into 0. 7nm manganate by losing one interlayer OH-H_2O, while those with stable structure still retained the 1nm d-spacing. This factor reminds us that the manganese nodule samples must be kept in wet condition to avoid the misleading results. The structural stabdity of 1nn manganate is mainly controlled by the interlayer divalent cations. There is a possitive correlation between the amount of cations in the interlayer and the structural stability, while the capacity of different canons in stabilizing the structure of 1nm manganate is as follows: Ni > Cu > Co > Zn > Ca>Mg > Na.